One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,11)(8,9)(10,12)(13,14,17,20)(15,18,19,16)(22,25)(23,27)(2,4)(6,8)(10,11)(13,15,17,19)(14,18,20,16)(1,2)(3,4)(5,6,9,8)(7,11,12,10)(13,16,17,18)(14,19,20,15)(21,22,24,25)(23,26,27,28)(5,7,9,12)(6,10,8,11)(21,23)(22,26)(24,27)(25,28)(5,8,9,6)(7,11,12,10)(13,14)(15,18)(16,19)(17,20)(21,23)(22,26)(24,27)(25,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.